hour with former NFL star Aaron Hernandez, back in court, pleading not guilty for killing two men outside of a nightclub. Hernandez is accused of gunning down three men in two, separate incidents. Ryan smith has the story. Reporter: This morning, Aaron Hernandez, the former new England patriots star tight end, defending himself against double-murder charges in the 2012 deaths of Daniel Abreu, and Furtado. Hernandez, awaiting trial for the 2013 murder of Odin Lloyd, entering the same plea in this case. As members of the families looked on in tears, prosecutors presenting their case against the football star. The defendant, Aaron Hernandez, armed with a .38 caliber revolver, shot and killed two men. Reporter: Saying the brutal killing stemming from the smallest of incidents. When at a nightclub, one of the victims bumped into Hernandez on the dance floor, spilling his drink. The defendant became angered and agitated after Mr. Deabreu smiled and did not apologize. Reporter: Even speeding through a red light to catch up to them. The defendant leaned out of the driver's side window of the SUV and stated, Yo, what's up now? And the defendant meetly fired phi rounds from a .38 caliber revolver into the victim's car. Reporter: Then, bragging about the killings. Hernandez's defense attorney taking exception to the prosecution's handling of the case, accusing them of grandstanding. But for now, Aaron Hernandez, facing two murder trials and potentially life behind bars. Hernandez's next court date in this case, is June 24th. But the Odin Lloyd case will be tried before this. Two murder trials? Reporter: Yep. One and then the other.

This transcript has been automatically generated and may not be 100% accurate.

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